The invention relates to a method of producing a linear graphic element on a molded body.
The molded body may, for example, be an operating element, a decorative design element or a display element, which are used for many different purposes. The linear graphic element may be a line, a straight line, or a figure which is closed in itself, such as a rectangle. By means of this figure, a design can also be achieved which acts as a bordering of a letter and can thereby be displayed as a letter.
In this context, a method of producing operating elements, decorative design elements or display elements, is known from German Patent document DE 42 12 423 C2, in the case of which a non-transparent layer, which is applied to a basic body, is removed by use of laser irradiation for producing a symbol. In this case, the layer is completely removed. Areas with or without coating, which visually can be clearly differentiated from one another, are present on the basic body. The laser is used only as a tool here, by which the coating is rapidly and completely removed. The faster the removal of the coating takes place, the shorter the machining time. The defining of a short machining time thus requires an energy-intensive machining of the coating and, therefore, involves the risk of damaging the basic body. This leads to a non-uniform visual appearance of the symbol.
This poor visual impression is further intensified if the element graphic should be recognizable also under less favorable light conditions, particularly in darkness. A person skilled in the art knows this design in the case of operating elements under the name of “night design”. For this purpose, it is known from German Patent document DE 42 12 423 C2 to shine a light source behind the basic body, so that the light can emerge through the places which are free of coating. Damage to the basic body in these areas has the visual appearance of dirt.
It is an object of the invention to improve the above-described method such that the graphic element has a uniform appearance when under different lighting conditions, and which method permits a fast and process-reliable production.
This object is achieved by a method of producing a linear graphic element on a molded body, wherein the molded body is metallically coated, and the graphic element is produced by a laser irradiation by which the coating is removed in the form of dots.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.